1. Field of the Invention
The present invention is related to an instantly welded antenna; and especially to such an antenna for a mobile phone, which antenna is suitable to be welded at the end thereof having a metallic seat member with superior heat conductivity to generate high temperature to partially melt an insulating plastic sleeve so as to instantly form a structure with a strong engaging force.
2. Description of the Prior Art
A helix coil formed by winding a metallic wire is the main element for transmitting and receiving frequency on an antenna. The structure of the helix antenna affects the function of the whole antenna in every aspect. The helix antenna as disclosed in British Patent No.2, 206,243 of which the diameter of wire of the coil, the material of the coil such as one made from copper plated steel, the core diameter, the pitch and the overall length of the helix coil etc. all affect its proper and set function.
Moreover, sometimes a mobile phone used nowadays have more than one frequency, such as two frequencies of 900 KHz and 1800 KHz, so it surely can be made to have a dual-frequency antenna by various methods and with various structures. The dual-frequency helical antenna of the British Patent No.2, 260,243 as mentioned above was made from a long helical coil and a linear conductor extended into the long helix coil. Among the modern designs of coils, even a single coil with sections of different density can form a dual-frequency antenna. No matter what kind of design of structure is adopted for the coil antenna for transmitting and receiving frequencies, to maintain the predetermined diameter, the pitch of the helix and the overall length of the coil antenna after production becomes quite important.
But among the processing methods for the presently available coil antennas, the most usually used method is to mount one end of the coil on the surface of the metallic seat member, then put it immediately into a mold to proceed to shaping by enveloping. The conventional method is not only inconvenient in processing, but also slow in production speed. The metallic seat member and the coil are put together in the mold to proceed to ejection enveloping of the insulating sleeve. The structure of the coil is hollow and spiral; this can easily affect the predetermined diameter of the coil, the pitch and the overall length of the helix coil. Rate of inferiority of the products thus becomes rather high under examination. This not only wastes working hours and material, but also increases the total cost of production indirectly.
The object of the present invention is to provide an instantly welded antenna of which a metallic seat member of the coil is made of better heat-conductive material such as copper family material, and an insulating sleeve is mainly made of the plastic family material. After assembling and positioning of the metallic seat member, the coil and the insulating sleeve as mentioned above, one end of the metallic seat member is heated up instantly; The heated surface can conduct heat to a welding surface formed at the peripheral surface of the metallic seat member and the relative inside surface of the insulating sleeve to generate a strong engaging and welding effect. Thus the production process will become more convenient and rapid; besides, the predetermined diameter of the coil, the pitch and the overall length of the helix coil can be maintained more effectively to lower the inferiority of the products.
The closer the distance between the heated surface and the welding surface as mentioned above is, the more suitable the shortening time of welding will be.
In principle, the above mentioned heated surface must be positioned slightly above the connecting position of the metallic seat member and the insulating sleeve to prevent deforming or damaging of the plastic insulating sleeve.
The above mentioned insulating sleeve can be made of engineering plastic of a mixture of plastic and rubber family material or of other family material, whereof, the ratio of the plastic family is most preferably more than 40%.
The heat-up temperature of the abovementioned metallic seat member and plastic insulating sleeve had better be 200xc2x0 C.-250xc2x0 C., and it is most preferred to give the metallic seat member pressurizing with a set stroke.
In a preferred embodiment, the metallic seat member provides a shoulder portion thereof as the heated surface, and the peripheral surface thereof used as a welding and connecting surface extends with a predetermined length thereof into a relatively inside stepped-hole portion of the insulating sleeve. Then the heated surface is heated up instantly and welding is engaged in under the pressurizing with a set stroke.
The present invention will be apparent in its novelty and other features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.